The design had reached 100% drawing release. It consisted of an integrated rocket booster, two ramjets for cruise, and XN-1 inertial navigation with a final dive on the target. But the inertial navigator drifted 1.6 km in accuracy for each hour of flight, which meant the missile could not meet the USAF 800 m CEP requirement.

USAF policy for development of earth satellites 'at the proper time'. - .
Nation: USA.
Related Persons: Vandenberg, Hoyt.
General Hoyt S. Vandenberg, Vice Chief of Staff, United States Air Force, approved a policy calling for the development of earth satellites at the proper time..

AF flight 20. Engine fire after launch forced jettisoning of propellants, completed as a glide flight. However Fitz-Gerald reached 12.1 km and reached Mach 1.10 before the engine was shut off, in the process becoming the second person to break the sound barrier.

The Navaho was redefined by the customer in a revised three-phase program using a rocket booster and ramjet cruise. Track, air, and vertical pad launch were to be studied. The first phase would produce a missile with a range of 1600 km while carrying a 1350 kg warhead. Phase two would produce a missile that could carry a 1350 kg warhead to a 3200 to 4800 km range. Phase 3 would be the intercontinental version, carrying a 4500 kg nuclear warhead to an 8000 km range.

Disagreement within US military on rocket roles - .
Nation: USA.
Key West Agreement formulated by military service chiefs which delineated respective service roles and missions. It did not clearly assign military aeronautical and rocket research and development responsibilities to the services..

Decree 'On work on the R-1 and R-2 missiles' was issued. To accomplish putting the R-1 into production the resources of 13 research institutes and 35 factories were tapped. Glushko was tasked with producing the RD-100 copy of the V-2 engine. R-1 stand tests began the same day the decree was issued (Prototypes had already begun factory tests at the end of 1947). The decree also set forth design goals for the R-3.The specification was an order of magnitude leap from the other vehicles - to deliver a 3 tonne atomic bomb to any point in Europe from Soviet territory - a required range of 3000 km.

XSSM-A-2 stellar-inertial navigation - .
Nation: USA.
Program: Navaho.
Preliminary design review of North American's XN-2 navigation platform, which coupled the XN-1 inertial system with a star tracker to ensure continued accuracy even in long flights..

1948 May 3 - .

Death of Howard Clifton 'Tick' Lilly - .
Nation: USA.
Related Persons: Lilly.
American test pilot. Flew the XS-1; died in a crash of the D-558-1..

First launch attempt of MX-770 technology demonstrator. Seven rockets were built in total. There is very inconsistent information on the flight series. One source speaks of six launches, another of four, and a third of three. It seems that there were six launch attempts, three of which never made it very far off the pad, two made it some distance aloft, and only one was considered somewhat successful (reaching Mach 2.23 and an altitude of 18 km).

North American began study of an advanced version of the Navaho, which would use a separate, jettisonable rocket booster. This would allow the cruise stage to be ignited at near-cruise velocity, and to be filled with only ramjet fuel, which would vastly extend the range. In this same month design of the XN-1 inertial navigator is completed.

Launched 03:22 local time. Reached 62.4 km. Carried pressure, temperature, composition, ionosphere, sky brightness, solar radiation experiments for Air Research and Development Command. Also carried Albert, the first American primate in space, who died of suffocation.

North American Aerophysics Laboratory moved to Downey. - .
Nation: USA.
Program: Navaho.

Together with the company's Electromechanical Division, the expanding group was moved into an ex-Consolidated Vultee bomber factory east of Los Angeles. It was here that the Navaho, and later Hound Dog missiles, the Apollo command module, and the Space Shuttle would be built.

MX-774 Flight 1 - .
Nation: USA.
Agency: USAF.
Apogee: 1.00 km (0.60 mi). First Convair MX-774 (RTV-A-2) test rocket was successfully launched, first demonstrating use of gimballed engines and design features later incorporated in the Atlas ICBM. This was the first of three Convair-sponsored test flights..

Photography research. Launched at 1441 local time. Reached 112.7 km. Two separate rockets fired from White Sands, one a V-2 which reached an altitude of 87 km, the other a Navy Aerobee which reached an altitude of 112.7 km, carried cameras which photographed the curvature of the earth.

Birth of Sharon Christa Corrigan McAuliffe - .
Nation: USA.
Related Persons: McAuliffe.
American teacher payload specialist astronaut. Flew on STS-51-L. Was to have been the first teacher in space. Died in Challenger accident..

Committee on Guided Missiles of the Research and Development Board approved recommendation that Army Hermes project "be given the task of providing the National Military Establishment with a continuing analysis of the long-range rocket problem as an expansion of their task on an earth satellite vehicle."

First views of earth from near-orbital height. - .
Nation: USA.
Photographs of the earth's surface taken from altitudes between 60 and 70 miles by cameras installed in rockets, were released by the Navy..

A paper read to the British Interplanetary Society by H. E. Ross described a manned lunar landing mission which would require a combination of the earth orbit and lunar orbit rendezvous techniques. Three spacecraft would be launched simultaneously into earth orbit, each carrying a pilot. After rendezvous, the crew would transfer to ship A, which would refuel from ships B and C. Ship C would be discarded completely, but ship B would be fueled with the surplus not needed by A. The spacecraft would then be fired into a translunar trajectory. Upon reaching the vicinity of the moon, the spacecraft would go into lunar orbit, detach fuel tanks, and descend to the lunar surface. To return to earth, the spacecraft would rendezvous with the fuel tanks, refuel, and fire into a transearth trajectory. On approaching the earth, the spacecraft would rendezvous with ship B, the crew would transfer to ship B, and descend to earth. The ability to rendezvous in space was seen to be the essential element of such a project. The total payload weight at launch would be 1,326 tons equally divided among the three ships as compared to 2.6 times this weight required for a direct ascent and return from the moon.

In a paper presented to the British Interplanetary Society, H. E. Ross described a manned satellite station in Earth orbit that would serve as an astronomical and zero-gravity and vacuum research laboratory. (Ross' bold suggestions also included schemes for a manned landing on the Moon and return to Earth through use of the rendezvous technique in Earth orbit and about the Moon.) Ross' suggested design comprised a circular structure that housed the crew of the space laboratory (numbering 24 specialists and support personnel) as well as telescopes and research equipment. The station, he suggested, could be resupplied with oxygen and other life-support essentials by supply ships launched every three months.

Jet Propulsion Centers established at Princeton University and the California Institute of Technology by the Daniel and Florence Guggenheim Foundation to provide research facilities and graduate training for qualified young scientists and engineers in rocketry and astronautics. Robert H. Goddard Chairs were established at each center.

The team defended the G-1 draft project on 28 December 1948. The State Commission found the G-1 to be superior to Korolev's R-2 design in many respects. However the Russian designers managed to convince the government to put the R-2 rather than the G-1 into production by arguing that the manufacturing technology of the G-1 could not be mastered immediately by Soviet Union. Several of the design concepts (integrated propellant tanks, radio-controlled cut-off, forward liquid oxygen tank) were however used by the Russians in their R-2 and R-5 rockets.

The first Secretary of Defense, James V. Forrestal, in his initial report to President Harry Truman, included a brief item indicating that the earth satellite program, which was being carried out independently by the military services, was assigned to the Committee on Guided Missiles for coordination.